Exercising control flow through OET to Tango devices through Observing scripts

Exercising the OET's ‘Observing Script to Observing Task’ interface and ‘Observing Task to TMC device’ interface will continue to establish the viability of the OET's core architecture and put in place the initial stages of being able to execute simple observations controlling virtual systems via TMC TANGO devices. This creates a platform that can be extended. The first extension - to be able to parse a simple SB instance - is proposed in SP-302.

Pre-condition: a sub array has been created using the resource allocation scripts developed in SP-142.

A simple observing script is executed taking as input arguments a set of pointing positions in RA,Dec, and a scan length. This script should run appropriate Observing Tasks that will configure the system and then scan to observe, for each pointing position.

The result of executing these Tasks is that configure and scan Tango commands are issued and the TMC prototype commands the virtual dishes in the sub-array to track at each pointing position(s) and scan at each position in a sequence.

NOTE: This should be a simple, first, observing script. It is expected to execute in a single thread, and there is no expectation of implementing the entire State Control Model.